Alberta researchers to record ground vibrations to look for fracking quakes

CALGARY - Researchers in Alberta are digging into a controversial technique used to extract natural gas and oil that some say causes earthquakes.

Teams from the University of Calgary and University of Alberta want to listen to hydraulic fracture treatments or fracking, as it's more commonly known.

"What it involves is installation of sensors that are called geophones, usually in a deep borehole, but sometimes also at the surface," David Eaton, a University of Calgary geophysics professor and lead investigator, said Thursday.

"The geophones are used to measure ground vibrations and if you measure ground vibrations at three or more locations, it's possible to then triangulate the location where seismic waves are created. And they're created at tiny, micro-earthquakes that occur during the frack treatment process."

Fracking involves pumping water, sand and chemicals deep down well bores to crack open fissures and boost the flow of oil and gas.

Eaton said researchers can track in real time where a fracture is going and where fluids used in the process end up.

"We do want to make sure that...fracks stay in the target zone where they're intended to go and also that they're aren't any concerns about triggering of earth tremors that might be above the threshold for magnitude that people would consider acceptable."

Eaton said the research will take place at locations in Western Canada.

The Natural Sciences and Engineering Research Council of Canada is providing half of the money for the three-year, $1.86 million university project.

"We do take the challenge very seriously to maintain high academic integrity through this project and our industry partners know this."

Opponents of fracking have raised environmental concerns about the amount of water the process requires, pollution from wastewater and the potential for earthquakes.

The B.C. Oil and Gas Commission, the province's energy regulator, said in a report released in September that fracking caused a spate of small earthquakes in B.C.'s remote northeastern corner.

The report said an investigation found that at least 38 quakes observed within remote and isolated areas of the Horn River Basin between 2009 and 2011 were caused by fluid injection during hydraulic fracturing near pre-existing faults.

The 38 events ranged between magnitudes of 2.2 and 3.8 on the Richter scale.

A quake of between 4.0 and 4.9 is considered "light" and may cause a noticeable shaking of indoor items and rattling noises.

The report also said more than 8,000 fracking completions have been performed in northeastern B.C. that haven't been associated with unusual seismic activity.

Earlier this year, a report by the National Research Council in the United States said hydraulic fracturing does not pose a high risk for triggering earthquakes large enough to feel.

It said only two worldwide instances of shaking — a magnitude 2.8 tremor in Oklahoma and a 2.3 magnitude shaking in England — can be attributed to hydraulic fracturing.

In Ohio, an injection well used to hold wastewater from the fracking process has been tied to a series of earthquakes in the Youngstown area.